Green Synthesis and Foliar Application of Copper Nanoparticles in Sunflower (Helianthus annuus L.) to Improve Physiological Parameters and Yield

Nanotechnology holds significant interest across various domains, including agriculture. The green synthesis of nanoparticles offers environmentally friendly solutions. This study aimed to synthesize copper nanoparticles (NPs) using Aloe vera extracts and evaluate their foliar application on two sunflower hybrids, Chané (Ch) and Calchaquí (Ca). The two types of Aloe Vera extracts used to produce nanoparticles were characterized by UV-vis spectral analysis and dynamic light scattering (DLS). The Np particles synthesized with Aloe vera Home (Np1) measured 242.8 nm (62.6%) and 74.87 nm (37.4%), while Aloe vera Commercial (Np2) resulted in sizes of 339.6 nm (90.7%) and 66.07 nm (9.3%). Two different doses of Np (150 ppm and 300 ppm) were applied to sunflower plants. We measured germination power (GP), plant height (PH), leaf number (LN), leaf area (LA), dry weight accumulation and achene yield. Chané’s parameters improved at both nanoparticle doses, while Calchaquí only improved with the 300 ppm treatment. This research highlights the potential use of green nanotechnology to improve growth and yield in sunflower. Highlights: • Nanoparticles, with unique physicochemical properties, have garnered significant attention in crop management strategies. • Aloe vera, popular for its medicinal and bioactive properties, is a compelling candidate for synthesizing copper nanoparticles, aligning with sustainable practices and offering biocompatible and eco-friendly nanomaterials for agriculture. • Sunflower (Helianthus annuus) is an emblematic oilseed crop known for its adaptability to various environments and the capacity to provide oil, seeds, and biomass. • This research aims to describe the mechanisms underlying nanoparticle-plant interactions, and how Aloe Vera-based copper nanoparticles affect growth, biomass accumulation and partitioning in two sunflower hybrids. • The Np particles synthesized with Aloe vera Home (Np1) measured 242.8 nm (62.6%) and 74.87 nm (37.4%), while Aloe vera Commercial (Np2) resulted in sizes of 339.6 nm (90.7%) and 66.07 nm (9.3%). • Chané's parameters improved at both nanoparticle doses (150 ppm and 300 ppm), while Calchaquí showed only improved with the 300 ppm treatment.